System of call distribution.



H. M. BASCOM. SYSTEM OF CALL DISTRIBUTION. APPLICATION FILED MAY 18. 19.15.

2 SHEETS-SHEET 1- vehzo/"f Hen/y M Boscom.

Patented Feb. 22, 1916;

H. M. BASCOM.

SYSTEM OF CALL DISTRIBUTION. APPLICATION FlLED MAY 18, 19l5.

1,172,760, I PatentedFeb. 22, 1916.

2 SHEETS-SHEET 2.

W/ff? asses:

by mil;

' HENRY M,

'-To all whom it may concern:

STATES- rarnnaionsrcu.

nasoom, or BROOKLYN, NEW YORK, as'sreivon. '10 AMERICAN TELEPHONE 'ANnarrE EenAPn COMPANY, A ooRroRA'rroN on NEW YORK.

- SYST'EM- CALL DISTRIBUTION.

-Be it known that I, HENRY M. BASCOM, residing at Brooklyn, in the .county of Kings and State of New York, have invented certain Improvements in Systems of Call Distribution, of which the followingis a specification.

The presentinvention is directed to sys temsfor giving individual access to an idle circuit of a group, asthe call or order circuits connecting the positions of subscribers operators and trunking operators, its chief objects being the provision of a simple and reliable system of-this character in which interfering connections are avoided and in which the circuits are used in rotation to effect a uniform distribution of the calls.

One embodiment ofthe invention appears in the accompanying drawiugs,'in which- Figures 1 and 2 placed in alinement, with Fig. 2 at .the right, represent diagrammatically the improved system applied to a plurality of call circuits connecting the positions of A and B-operators.

X,'X and X designate the first, second and last of a series of positions belonging to subscribers or A-operators, at which the usual operators equipment is conventionally indicated by a telephone set T. Through these positions extend call circuitsL, L and L terminating at the positions Y, Y and Y of trunking or B-operators, there being a sufiicient number of these B-operators and the corresponding call circuits to satisfy the requirements of the entire series of A-operators. The Boperators have the customary equipment t, and are also preferably provided with a contact device y at each position which maintains a closure of one side' of the callcircuit when the position is 00- cupied but which is opened when the B-operator leaves her position.

Of-the'apparatus belonging more par-i ticularly to this improved system, there is at each A-operators position a manual call circuit connection-initiating device or k ey K, which, in addition to contacts for joining the operators set T to the call circuitleads Z, has a contact for applying current from battery I) to the winding of a connectioninitiating relay or other suitable electromagnetic device B- through back contacts of connecting relays R in series andthen back to battery for the relay R of'the first position X, or, for such relays of any of the R has also afront contact in the energizing j circuit of each of the relays R These v Patented Feb. 22, 1916-. Application filed May 18, 1915. Serial No. 28,914. j

latter relays are in a group equal in 'num-,

her to the call circuits apportioned to the A-positions. {At their back contacts in series call circuit leads Zare united throughl-a' re-,

pe'ating'coil I toasource S of'tone, when all the call circuits are in use, At the front 'contacts'the leads Z are connected, either directly, if the first call, circuit L is idle, or

through the back contacts of preceding connecting relays ifsome are busy, to the cor-- responding call circuit. The windings of each group of relays R are joined in multithe closure of this key and the consequent. energization of relay R all the connecting relays are prepared for operation. Which of these will be actuated to unite its call circuit to the leads Z'is determined by a group of controlling relays R common to all the A-positions and including a relay for each call circuit. A back contact of eachiof the controlling relays is multipled to the windings of the corresponding relays R at all the A-positions through a front contact of the initiating relay R at each such position. The armature of relay of the first call circuit L cooperating with this contact is connected to battery, while the armature of thesucc'eeding relay B is joined to the front contact of the relay preceding it in the group. Theifront contact of the last relay R is carried to battery through the windings of a release relay B.

As the connecting'relayat any A-position is energized, it completes at a front contact the circuit of one winding of the relay R associated with thesame call circuit. This, attracting its armatures, severs at its back contact the energizing circuits of all the other connectin'g'relays for this call circuit and transfers at its front contact the battery connection to the connecting relays of the next call circuit. This continues in rotation until all the call circuits have been put into-use. At a front contact each relay R except that of the last circuit L furnishes a locking circuit through a second winding of the relay to battery at the back Y plc to battery at the key K, so that upon contact of the release relay R The connection of the controlling relay for the first call circuit L to this holding circuit is direct, while that of the others is through the front contacts of the relays preceding them in the group. By thisarrangement each control ling relay, as it acts as a result of the operation of one of the corresponding connecting relays, locks its call circuit from use and sequentially renders the neXt circuit of the group effective, this continuing until the last call circuit L has been utilized. Then re lease relay R operates, opening the locking circuit through the right hand windings of the controlling relays. The calls of the A- operators are therefore uniformly distributed among the entire group of circuits. At its front contact R supplies current to a lamp 0 or operates some other signal. to

show that all the circuits are busy.

To permit a call circuit to be temporarily disabled, so that, for example, an operator may leave her position, a relay R is associated with each circuit with one end of each of its double windings joined to the call circuit conductors and the other extremities united to battery 6 At its back contact relay R connects battery through a resistance r to the left hand winding of the controlling relay R of the same call circuit. So long as the B-end of the circuit is closed through the contact device 3 the relay R remains energized, holding the path through the resist ance .7 open, but when the call circuit is broken at 3/ relay R releases and relay R operates, thus severing the circuit of the relay R belonging to this call circuit at all positions. Calls are therefore diverted from the latter as long as this condition is maintained. Condensers C are included in each call circuit between connections of relay R and the A-positions, to prevent current from battery flowing back over the call circuits to the A-positions and the repeating coil 1 thereat and causing false operation of the circuit.

To describe the operation of the system in detail, it may first be assumed that all the call circuits are idle and that the A-operator at the last position X", desiring the assignment of a trunk by a B-o'perator, depresses her key K. Current flows from battery 7) through contact 10 of the key, conductor 11, successively through the back contacts 12 of all the connecting relays R winding of the initiating relay R, conductor 13 and back contacts 13 of the initiating relays at all positions back to battery. There are now cir cuit branches from battery and conductor 11 through conductors l5, windings of relays R conductors 16, front contacts 14 of relay R conductors 17 to the back contacts 18 of controlling relays R All the call circuits being idle and the arniatures of relays B being retracted a battery connection exists only at the relay associated R of circuit L is operated and breaking its I,

back contact'12 opens the initiating circuit of relay R, which releases, preventing th energization of other connecting relays at the same position. At front contacts 20 the common leads Z are united to the call cir .75

cuit L, and since these leads are connected to the A-operators set at contacts 21 of the key,-saiel operator is in connection with a B-operator over circuit L and may give the number wanted and receive a trunk assignment. At back contacts 22 relay R opens the circuit for. the leads Z through the back contacts of the succeeding relays R to the source S of the busy tone. A branch 23 from conductor 16, including windin of the first controlling relay R is completed at the front contact 24 of relay R Relay R is thereby energized and transfers the battery connection from contact 18 to contact 19, thus preventing connecting relays for the call circuit L at'other A-positions from operating and preparing for the operation of such relays of circuit L The originating circuit for the connecting relay is opened. but it is locked in series with the winding 0 relay R Front contact 26 of relay R close an independent locking. circuit through wlnding 27 of this relay, conductor 28 and back contact 29 of the release relay R WVhen use of the circuit L is completed by the operator at position X-she releases the key K. This at contact 10 denergizes the connecting relay, restoring the call circuit equipment individual to the position to its normal condition and opening the originating circuit of the controlling relay through winding 25. The latter relay remains energized on account of the locking circuit through winding 27.

If another A--operator actuates her key K when the circuit L is still in use, or at any time before the selection of another call cir. cuit, the second of the group of connecting relays R at her position, or thatbelonging to the circuit L will be operated by a circuit as previously traced, but including the back contact 18 of controlling relay R associated with circuit L and front contact 19 of relay R belonging to circuit L. Relay R of circuit L is thereupon locked through its contact 26 and like contact of the previously energized relay R This selection continues until every call circuit of the group has been put into use. hen the last of these, L is reached, the energization of release relay R is effected by a circuit comprising conductor 30 and the contacts 19 of all the controlling relays in series. This withdraws the armature from contact 29 and the locklng circuit of the controlling relays through con- I ductor 28 is severed, causing the retraction of all said relays, the circuits through wind-' ings 25 of which do'not remain closed. Release relay Risdenergized by the openingof any one of the contacts 19. Upon the as all the controlling relays are energize At this time actuation by an A-operator; of key K applies a tone to her receiver, be-

cause 'none of the connecting relays R at the position respond and the tone generating device is joined to the leads Z'through the back contacts of all said relays in series.

depress their keys K at the same time while there were call circuits available for use, the

one whose position was nearest the battery' connectionat theresting-contact 13 of'relay R at position X would firstbe connectedto a call circuit, the opening of the correspond- .ing contact at said operators position barring those at positions farther removed by severing the initiating circuit. Upon the release of relay R of the successful operator and the closure of contact 13, the next in order would obtain a call circuit, and so on.

If it is desired to discontinue the use of one or more call circuits their contacts y are separated and the corresponding relays R released, these having been energized by current from battery 6 through winding 32, one side of the call circuit, the B-operators equipment, contact y, the other side of the call circuit and Winding 83. The windings 25 of relays R of these circuits now receive current by way of conductor 23, re-

sistance 1' and back contact 34 of relay R This produces the same effect as though these call circuits were in use, or as though .after use the rotation through the group.

had not been completed. To restore the disabled circuits, the contacts y are again.

closed, respectively energizing and releasing the corresponding relays R and R when the circuits may be selected as before.

I claim:

1. In a telephone system, the combination with a plurality of telephone sets, of a plurality of circuits, a group of devices individual to a telephone set for connecting the same to an idle circuit and containing one of saiddevices for each circuit, a connection-initiating device for preparing all the connecting devices for operation, and means for determining the operation of the connecting devices in'said groups in rotation.

2. 'In a telephone system, -the combination with a plurality of telephone sets, of a plurality of circuits, a. group of devices individual to a telephone set for connecting the same to an idle circuit and containing one of said devices for each circuit, a connection initiatingdevice for preparing all the con- I ,devices in said groups inrotation. Ifa plurality-of Aroperators chanced to necting devices for; operation, and means individual to each circuit for determinlng the operationfof the connecting devices in groups Fin; rotation. 3. In atelephone sys'tem,'the combination with a plurality joftelephone sets, of ap-lu-' rality of ci rcuits,a group of devices indi- .yidual tota telephone set for connecting'the: sametoan idle circuit and containing one of said devices for each circuit, a connection-- I initiating device for preparing all the connecting devices for operation, and means governed'bythe connecting devices for de- 'termining the operation of the connecting so ll In a system of call distribution, the

' combination with a plurality of telephone sets, of a pluralityof call'c'ircuits, a group of devices individual toa telephone set simultaneously available for connecting the same to an idle call'circuit and containing one of said devices for each call circuit, and ,a'

group of devices common to the plural telephone sets and containing devices individual same to an idle call circuitand containing .one of said devlces'for each call ClIQllltfaIld.

a group of devices common to theplural telephone sets and containing devices individual to each call circuit for controlling the operation of the connecting devices in rotation, these controlling devices being dependent for their operation upon the condition of the connecting devices." 6. A plurality of telephone sets, a group of call circuits, means for connectingatele phone set to an idle call'circuit, and means, individual to each call circuit for preventing repeated connection of a call circuit with the telephone sets until all the other call circuits of the group have been utilized. 7. In a] system of call distribution. the combination with a plurality oftelephone sets, of a plurality of call circuits, devices individual to the call. circuits operable to control the connection of a telephone setto an idle call circuit, and means for preventing the repeated operation of a controlling device until all the associated devices have been operated. I

8. A plurality of operators positions and a plurality of call circuits associated therewith, a device at each position individual to each call circuit for'renderlng a call circuit available at said posit on,- and means for :c'ausing the operation of one of saiddevices and for preventing the operation of .other devices. 7

10, A plurality of operators positions'and a plurality of call" circuits associated there= with, a device at each position individual to each call circuit for rendering a call clrcuit i available at said position, and means for initiating the operation of certain of said'de- V1065, said initiating means lncludlng means for preventing the operation of other ofthe being joined directly to the connecting devices of diiferent positions, and adapted to remain energized till all the call circuits have been utilized.

12. A plurality of operators positions, a plurality of call circuits associated with said positions, an initiating relay at each position, a group of electromagnetic connecting devicesat each position provided with energ'izing windings and rendering a call circuit effective thereat, and a group of electromagnetic controlling devices for preventing connection to a busy call circuit, the energizing windings of the connecting devices of different positions being multipled directly to the contacts of a controlling device and extending through. contacts of said relays.

13. A plurality of operators positions, a plurality of call circuits associated With said. positions, agroup of electromagnetic connecting devicesat each position having contacts and being adapted to render a call circuit effective at such positions, a group of electromagnetic controlling devices for preventing connection to a busy call circuit, and energizing circuits for the controlling devices multipled to contacts of the connecting devices of different positions and means for locking said devices in rotation.

11-. A plurality of operators positions, a plurality of call circuits associated with said positions. electromagnetic connecting device's therefor, electromagnetic controlling devicesfor the connecting devices, energi7. ing circuits for the controlling devices governed by the connecting devices. and a cir i-uit independent of the connecting devices for continuing the energization of the controlling devices.

15. A plurality of operators positions. a I

plurality of call circuits associated with said positions, a group of electromagnetic contion, and means for unlocking thecont rolling devices atter'the entire energized. I 16. A plurality of operators positions, a

plurality of call circuits associated with said.

positions, a "group otelectromagnetic connecting devices at each position forrenden ing a call circuit effective thereat, agroup 0t electromagneticcontrolling devices for the connecting devices, means for locking" each controlling device upon its energization, means for unlocking the controlling devices, and 'a signal governed by the unlocking-means.

17. A plurality of operators positions, a

plurality of call circuits associated with said positions, an operators connection-initiating relay, a plurality of electromagnetic call circuit connecting devices inultipled to the initiating relay, and means associated with the call circuits whereby the connecting device afifected by the initiating relay is determined.

18. The combination with a plurality of operators positions each having a telephone set and a call circuit key, of call circuits extending through the positions, a group of relaysat each position having normally closed contacts connected to the key and contacts arranged to join the telephone set to a particular call circuit, and means for controlling the operation of the relays.

, 19. The combination with a plurality of operators positions each having a telephone set and a call circuit key, of call circuits extending through the positions, a group of relays at each position having contacts connected in series to the key and contacts arranged to join. the telephone set to a par; ticular call circuit, and means for controlling the operation of the relays.

20. The combination with a plurality of operators positions each havinga telephone set, of call circuits extending through the positions, an initiating relay at each position, and agroup of relays at each position having their windings connected to contacts of the initiating relay. said relays having contacts arranged to join the telephone set to a' particular crll circuit and other contacts in series with the winding of the initiating relay.

21. The combination with a plurality of operators positions each having a telephone set and a call circuit key, of call circuits extending through the positions, an initiating relay at each position, a group of call circuit connecting relays at each position started in operation by the initiating regroup has been lay, and an energizing'ci rcuit for the initiating relay including-fa j.contact-'of the key and'back contacts of thefconnecting relays in'series. k p

22. The combinatiofi'with aplura'lity of operators positions'eafchhaving a telephone set, of call circuits.e x-tending through the positions, an initiatin" tion a on of call'circuit connectin relays at each position started inoperation' by theinitiating relay, and an energizing circuit for the initiating relay at each pos tioninc'luding the back contacts of the im tiatin {relays at other positions.

2'31 he'combination with a plurality of o call circuits, of a plurality o operators positions each proyidedfwith a telephone set,g-an initiating relay and electromagnetlc means for connecting an idle" call circuit thereto and controlled by said initiating re- 'layyof controlling relays assoc ated with the call circuits, and an energizing'circuit for the connecting means comprisl'ngrthe contacts of a plurality of thecontrolli ngrej;

lays. 1-24; The combination with a plurality of callcircuits, of a plurality of operators po-- sitions each provided with a telephone setand electromagnetic means for connecting an idle call circuit thereto, of controlling relays for the connecting means, an energizing circuit for eachcontrolling relay governed by the connecting means, and a locking circuit for controlling the relays inrof tation.

26. The combination with a plurality of y' at eachv posicall circuits, of a plurality of operators positions each provided with a telephone set and electromagnetic means for connecting an idle call circuit thereto, ofcontrolling relays forthe connecting means, an energizing circuit for each controlling relay gov.- erned b the connecting means, a locking circuitv or the controlling relays, and a release relay governing thelocking circuitl Y 27. The combination with a plurality of; call circuits, of a plurality of operators po sitions each provided with a telephone set and electromagnetic m'eansfor connecting an idleicall circuit thereto, of controlling relays for the connecting means, an energizing circuit for each controlling relaygoverned by the connecting means, a lock-.

ing circuit for the controlling relays, a release relay governing the locking circuit,

and a signal controlled by the releaserelay,

28. The combination with apluralityof call circuits, of a plurality of operators positions'each' provided with a telephone -set and electromagnetic means for connecting an idle call circuit theretofof controlling relays for the connecting means,"an' energizing circuit for each controlling relay governed by the connecting means, a locking I circuit for the controlling relays, a release relay governing the lockingcircuit, and an energizlng circuit forthe releaserela'y extending through the 'front contacts of the controlling relays. 29. The combinationvwith a plurality of operators positions each having a telephoneset and acall circuit key, of call circu ts extending through the positions, a group of relays at each position having contacts connected in series to the key and OOIltitCtS'fiI- ranged-to join the telephone set to a particular call circuit, and means for controlling the operation of the relays in rotation.

In testimony whereof, I have signed my name to this specification in the presence of 'two subscribing witnesses, this 13th day of May, 1915. l

I HENRY M. BASGOM. Witnesses:

SAMUEL RASMISIN, HARRY L. BROWN. 

